SALT LAKE CITY — Bald eagles are dying in Utah — 20 in the past few weeks alone — and nobody can
figure out why.

Hundreds of the majestic birds, many with wingspans of 7 feet or more, migrate here each winter,
gathering along the Great Salt Lake and feasting on carp and other fish that swim in the nearby
freshwater bays.

Earlier this month, however, hunters and farmers across five counties in northern and central
Utah began finding the normally skittish raptors lying listless on the ground. Many suffered from
seizures, head tremors and paralysis in the legs, feet and wings.

Many of the eagles were brought to the mammoth Wildlife Rehabilitation Center of Northern Utah,
where Buz Marthaler, a longtime animal caretaker, and other handlers tried to save the birds.
Within 48 hours most were dead.

“In an average year, we might get one or two (eagles), but we’ve received nine so far, and five
of those have died,” Marthaler said. “The other four are still in our care.”

Marthaler, 56, co-founder of the facility in Ogden, said, “It’s just hard to have your national
bird in your arms, going through seizures in a way it can’t control — when you can see its pain but
don’t know what’s happening to it.”

State wildlife specialists are baffled. For weeks, officials have sent birds for necropsies at
the National Wildlife Health Center in Madison, Wis., hoping the results would offer clues.

The birds were not shot by hunters, and officials don’t believe the birds were poisoned.

At first, the agency’s disease scientists guessed that the illness could be encephalitis, which
is caused by the West Nile virus, but later ruled that out. And although many sick eagles tested
positive for lead, researchers did not think that it was killing the birds.

Officials now suggest the eagle die-off might be connected to the deaths of thousands of eared
grebes that began in Utah in November. Eagles are known to prey on the small shorebirds. Because
the grebes are thought to have died from avian cholera, many scientists theorize that the eagles
became sick from feeding on infected grebes. Officials still don’t know why the shorebirds became
sick.

“We’re getting closer to an answer,” said Mitch Lane, a conservation officer with the Utah
Division of Wildlife Resources, adding that officials would meet this week to continue
investigating.